<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<meta name="description" content="始终将main主体内容放在前面显示">
	<style type="text/css">
		html, body {
			margin: 0;
			padding: 0;
			height: 100%;
		}
		.layout__main-wrapper {
			width: 100%;
			height: 100%;
			float: left;
		}
		.layout__main {
			height: 100%;
			margin: 0 210px;
			background-color: #CC9933;
		}
		.layout__aside-left {
			height: 100%;
			float: left;
			width: 200px;
			margin-left: -100%;
			background-color: #009966;
		}
		.layout__aside-right {
			height: 100%;
			float: left;
			width: 200px;
			position: relative;
			margin-left: -200px;
			background-color: #4DBCB0;
		}
	</style>
</head>
<body>
	<div class="layout__main-wrapper">
		<div class="layout__main">主内容栏宽度自适应</div>
	</div>
	<div class="layout__aside-left">左侧边栏宽度固定</div>
	<div class="layout__aside-right">右侧边栏宽度固定</div>
</body>
</html>